Functional assessment of heart-specific enhancers by integrating ChIP-seq data.

BACKGROUND: Identification and functional annotations of regulatory sequences play a pivotal role in heart development and function. METHODS: To generate a map of human heart-specific enhancers, we performed an integrative analysis of 148 chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) samples with enhancer-associated epigenetic marks from the heart, liver, brain, and kidney. Functional validation of heart-specific enhancer activity was then performed using cultured cells. RESULTS: A 144.6-Mb candidate heart-specific enhancer compendium was generated by integrating the analysis of 148 epigenomic data sets from human and mouse hearts and control tissues. To validate in vivo enhancer activity, we tested 12 of these sequences around 45 CHD-related genes in cultured cells and found that 8 (67%) have reproducible heart-specific enhancer activity. A functional analysis demonstrated that the identified human heart-specific enhancer wf1 regulates the FBN1 gene which is involved in heart disease. CONCLUSIONS: Our study provides an integrative analysis pipeline for ChIP-seq data and identified a comprehensive catalog of human heart-specific enhancers for clinical CHD-related studies. IMPACT: Establishing an efficient way to analyze regulatory regions in CHD is very important. A highly qualified heart-specific enhancer compendium was generated by integrating 148 online ChIP-seq samples. Sixty-seven percent of predicted regulatory sequences have reproducible heart-specific enhancer activity in vivo. Human heart-specific enhancer wf1 regulates the CHD-related FBN1 gene.

Size-segregated particle number concentrations and outpatient-department visits for pediatric respiratory diseases in Shanghai, China.

BACKGROUND: Few studies have simultaneously explored which size of particles has the greatest impact on the risk for pediatric asthma, bronchitis and upper respiratory tract infections (URTIs). OBJECTIVES: To investigate the short-term association between size-segregated particle number concentrations (PNCs) and outpatient-department visits (ODVs) for major pediatric respiratory diseases. METHODS: Daily counts of pediatric ODVs for asthma, bronchitis and URTIs were obtained from 66 hospitals in Shanghai, China, from 2016 to 2018. Pollutant effects were estimated using Poisson generalized additive models combined with polynomial distributed lag models. We also fitted co-pollutant cumulative effects models included six criteria air pollutants and conducted stratifying analyses by gender, age, season and geographic distances. RESULTS: We identified a total of 430,103 patients with asthma, 1,547,013 patients with bronchitis, and 2,155,738 patients with URTIs from the hospitals. Effect estimates increased with decreasing particle size. Ultrafine particle (UFP) and PNCs of 0.10-0.40 µm particles (PNC0.10-0.40) were associated with increased ODVs for asthma, bronchitis and URTIs at cumulative lags up to 3d. Associations tended to appear stable after adjusting for criteria air pollutants. At the cumulative lag 0-2d, each interquartile range increase in UFP was associated with increased ODVs due to asthma (relative risk 1.21, 95% CI: 1.07, 1.38), bronchitis (1.20, 95% CI: 1.07, 1.34) and URTI (1.17, 95% CI: 1.06, 1.30), whereas the associations for PNC0.10-0.40 remained significant but attenuated in magnitude. CONCLUSIONS: UFP may be a leading contributor to the adverse respiratory effects of particulate air pollution and the effects increased with decreasing particle size.

High maternal blood lipid levels during early pregnancy are associated with increased risk of congenital heart disease in offspring.

INTRODUCTION: This study aimed to investigate whether maternal blood lipid levels during early pregnancy are associated with the occurrence of congenital heart disease (CHD) in their offspring. MATERIAL AND METHODS: In this single-center case-control study, mothers of offspring with CHD (n = 230) and without CHD (n = 381) were included. Maternal lipid levels were determined on fasting blood samples taken in the first trimester. Relevant demographic and clinical data were extracted from the medical records. Maternal lipid profile was compared between the two groups, and regression analysis was performed to evaluate the association between lipid profile and CHD risk in offspring. RESULTS: Compared with the control group, levels of triglyceride, apolipoprotein-A1, and apolipoprotein-B in early pregnancy were significantly higher in the CHD group. Multivariate analyses showed that triglyceride (odds ratio [OR] 2.46, 95% CI 1.62-3.73, p < 0.01), total/high-density lipoprotein cholesterol (OR 2.10, 95% CI 1.07-4.13, p = 0.03), and apolipoprotein-A1 (OR 2.73, 95% CI 1.16-6.40, p = 0.02) were positively associated with CHD risk in offspring. CONCLUSIONS: Elevated maternal lipid profile was associated with increased risk of CHD in offspring.

Characteristics of childhood allergic diseases in outpatient and emergency departments in Shanghai, China, 2016-2018: a multicenter, retrospective study.

BACKGROUND: The prevalence of allergic diseases (ADs), such as asthma and allergic rhinitis (AR), is increasing worldwide in both adults and children. Although ADs are common and frequently coexist in outpatient care, city-level data regarding the characteristics of childhood AD remain limited in China. This study aimed to assess the profile and characteristics of ADs in the city of Shanghai. METHODS: A multicenter retrospective study was designed to collect routine administrative data from outpatient and emergency departments from 66 hospitals in Shanghai, China, from 2016 to 2018. Children with asthma, AR, allergic conjunctivitis (AC), and allergic skin diseases were investigated. Demographic characteristics, patients visit pattern, spectrum of diagnosis, and comorbidities were analyzed. RESULTS: A total of 2,376,150 outpatient and emergency visits for ADs were included in the period from 2016 to 2018. Allergic skin diseases accounted for 38.9%, followed by asthma (34.8%), AR (22.9%), and AC (3.3%), with a male predominance in all four diseases. Asthma and allergic skin diseases were most frequent in the 1 to < 4 years of age group, while AR and AC were more common in the 4 to < 7 years of age group. Asthma accounted for the greatest number of annual and emergency visits. The most frequent comorbidity of asthma was lower respiratory tract infection (LRTI) (49.3%), followed by AR (20.5%) and upper respiratory tract infection (14.1%). The most common comorbidities of AR were otitis media (23.4%), adenoid hypertrophy/obstructive sleep apnea (22.1%), followed by LRTI (12.1%), asthma (9.4%) and chronic pharyngitis (8.9%). CONCLUSIONS: Asthma and allergic skin diseases were the most common ADs in outpatient and emergency departments in the study period. Respiratory tract infection was the most common comorbidity of asthma in children. More attention should be devoted to the treatment of comorbidities to improve childhood AD outcomes with a better understanding of the characteristics of ADs in outpatient care.

Temperature changes between neighboring days and childhood asthma: a seasonal analysis in Shanghai, China.

Few evidences are available about the impact of temperature variation on childhood asthma in different seasons. This study aimed to assess the influence of temperature changes between neighboring days (TCN) on the exacerbation of asthma among children. Daily outpatient visits for childhood asthma (DOVCA) were collected from 17 main hospitals in Shanghai, China, from 2016 to 2018. A quasi-Poisson regression combined with distributed lagged nonlinear models was employed to estimate the association between TCN and asthma visits in cool or warm seasons, after controlling for short- and long-term trends, day of week, holidays, daily mean temperature, daily mean relative humidity, and air pollutants. The TCN varied from - 9.6 to 6.7 °C. The relationship between TCN and DOVCA greatly varied by season. In warm seasons, positive TCN (temperature rise) was associated with higher risks of asthma outpatient visits and negative TCN (temperature drop) was associated with lower risks; the associations were present on lag 1 day and lasted for 2 weeks; the cumulative relative risk of childhood asthma over 0 to 14 days was 1.98 (95% confidence interval: 1.42, 2.76) and 0.31 (95% confidence intervals: 0.21, 0.44) comparing a TCN of 2.5 °C (5th percentile) and - 3.2 °C (95th percentile) with 0 °C, respectively. In cool seasons, neither negative nor positive TCN showed significant risks. In conclusion, temperature rise might increase the risk of childhood asthma exacerbation and temperature drop might decrease the risks in warm seasons. There were no statistically significant influences in cool seasons.

Folic acid supplement rescues ethanol-induced developmental defects in the zebrafish embryos.

Fetal alcohol syndrome (FASD) describes a range of birth defects. Mechanisms of FASD-associated defects are not well understood. It has great significance to investigate whether nutrient supplements like folic acid (FA) can effectively rescue ethanol-induced defects. Moreover, it is very important to determine the optimal time for FA supplementation when it can most effectively antagonize the teratogenic effects of ethanol during embryonic development. Our results indicated that ethanol exposure interrupted the development of zebrafish embryos and induced multiple defects in cardiac function, pharyngeal arch arteries, vessel, craniofacial cartilage, pharyngeal arches, brain, somite and hemoglobin formation. The expressions of critical genes that play important roles in above organs such as tbx1, flk-1, hand2, ngn1, huc, titin, gata-1 and c-myb were reduced, and the apoptosis was increased in ethanol-treated group. FA supplementation could reverse ethanol-induced defects, improve the decreased expressions of above genes and reduce the apoptosis. We also found that giving FA at 6-12 h post-fertilization (hpf), which is at the gastrula period (5.25-10 hpf), can obviously prevent the teratogenicity of ethanol. This research provides clues for elucidating the mechanism of fetal abnormalities caused by alcohol intake and for preventing FASD.

Identification of a 42-bp heart-specific enhancer of the notch1b gene in zebrafish embryos.

BACKGROUND: NOTCH1 plays a key role in the differentiation of ventricles, and mutations are strongly associated with both sporadic and familial bicuspid aortic valves. However, few heart-specific enhancers have been identified to date. RESULTS: In this study, we investigated evolutionary conserved regions (ECRs) that might act as potential enhancers within the region approximately 150-kb upstream and downstream of the NOTCH1 gene. Functional validation revealed that one 127-bp ECR located ~85-kb downstream of the NOTCH1 gene drives green fluorescent protein expression in the zebrafish embryo heart. Transcription factor (TF) prediction and core TF distribution analyses were performed to identify the core region. Dissection of ECR3 was performed to identify the 42-bp sequence, which is sufficient for heart-specific expression. In situ hybridization experiments showed that notch1b is expressed in the heart. Overexpression experiments in cells indicated that NKX2-5 is critical for enhancer activity. Mutation of the NKX-5 binding site significantly decreased reporter gene expression. Next, compared with the commonly used myocardium-labeled zebrafish transgenic strain Tg(cmlc2: mCherry), this 42-bp enhancer-labeled stable line mediated a similar expression pattern but with a smaller core region. CONCLUSION: This study identified a 42-bp heart-specific enhancer near the NOTCH1 gene and further verified its functional targeting by NKX2-5.

[Effect of dhfr gene overexpression on ethanol-induced abnormal cardiovascular development in zebrafish embryos].

OBJECTIVE: To study the effect of dhfr gene overexpression on ethanol-induced abnormal cardiac and vascular development in zebrafish embryos and underlying mechanisms. METHODS: dhfr mRNA was transcribed in vitro and microinjected into zebrafish fertilized eggs to induce the overexpression of dhfr gene, and the efficiency of overexpression was verified. Wild-type zebrafish were divided into a control group, an ethanol group, and an ethanol+dhfr overexpression group (microinjection of 6 nL dhfr mRNA). The embryonic development was observed for each group. The transgenic zebrafish Tg (cmlc2:mcherry) with heart-specific red fluorescence was used to observe atrial and ventricular development. Fluorescence microscopy was performed to observe the development of cardiac outflow tract and blood vessels. Heart rate and ventricular shortening fraction were used to assess cardiac function. Gene probes were constructed, and embryo in situ hybridization and real-time PCR were used to measure the expression of nkx2.5, tbx1, and flk-1 in the embryo. RESULTS: Compared with the ethanol group, the ethanol+dhfr overexpression group had a significant reduction in the percentage of abnormal embryonic development and a significant increase in the percentage of embryonic survival (P<0.05), with significant improvements in the abnormalities of the atrium, ventricle, outflow tract, and blood vessels and cardiac function. Compared with the control group, the ethanol group had significant reductions in the expression of nkx2.5, tbx1, and flk-1 (P<0.05), and compared with the ethanol group, the ethanol+dhfr overexpression group had significant increases in the expression of nkx2.5, tbx1, and flk-1 (P<0.05), which were still lower than their expression in the control group. CONCLUSIONS: The overexpression of the dhfr gene can partially improve the abnormal development of embryonic heart and blood vessels induced by ethanol, possibly by upregulating the decreased expression of nkx2.5, tbx1, and flk-1 caused by ethanol.

Impact of DNA methyltransferase inhibitor 5-azacytidine on cardiac development of zebrafish in vivo and cardiomyocyte proliferation, apoptosis, and the homeostasis of gene expression in vitro.

Cardiac development is a peculiar process involving coordinated cellular differentiation, migration, proliferation, and apoptosis. DNA methylation plays a key role in genomic stability, tissue-specific gene expression, cell proliferation, and apoptosis. Hypomethylation in the global genome has been reported in cardiovascular diseases. However, little is known about the impact and specific mechanism of global hypomethylation on cardiomyocytes. In the present study, we explored the impact of DNA methyltransferase inhibitors 5-azacytidine on cardiac development. In vivo experiment showed that hypomethylation of zebrafish embryos with 5-azacytidine exposure significantly reduced survival, induced malformations, and delayed general development process. Furthermore, zebrafish embryos injected with 5-azacytidine developed pericardial edema, ventricular volume reduction, looping deformity, and reduction in heart rate and ventricular shortening fraction. Cardiomyocytes treated with 5-azacytidine in vitro decreased proliferation and induced apoptosis in a concentration-dependent manner. Furthermore, 5-azacytidine treatment in cardiomyocytes resulted in 20 downregulated genes expression and two upregulated genes expression in 45 candidate genes, which indicated that DNA methylation functions as a bidirectional modulator in regulating gene expression. In conclusion, these results show the regulative effects of the epigenetic modifier 5-azacytidine in cardiac development of zebrafish embryos in vivo and cardiomyocyte proliferation and apoptosis and the homeostasis of gene expression in vitro, which offer a novel understanding of aberrant DNA methylation in the etiology of cardiovascular disease.

Susceptibility to congenital heart defects associated with a polymorphism in TBX2 3' untranslated region in the Han Chinese population.

BACKGROUND: Tbx2 plays a critical role in determining fates of cardiomyocytes. Little is known about the contribution of TBX2 3' untranslated region (UTR) variants to the risk of congenital heart defect (CHD). Thus, we aimed to determine the association of single-nucleotide polymorphisms (SNPs) in TBX2 3' UTR with CHD susceptibility. METHODS: We recruited 1285 controls and 1241 CHD children from China. SNPs identification and genotyping were detected using Sanger Sequencing and SNaPshot. Stratified analysis was conducted to explore the association between rs59382073 polymorphism and CHD subtypes. Functional analyses were performed by luciferase assays in HEK-293T and H9c2 cells. RESULTS: Among five TBX2 3'UTR variants identified, rs59382073 minor allele T carriers had a 1.89-fold increased CHD risk compared to GG genotype (95% CI = 1.48-2.46, P = 4.48 × 10-7). The most probable subtypes were right ventricular outflow tract obstruction, conotruncal, and septal defect. G to T variation decreased luciferase activity in cells. This discrepancy was exaggerated by miR-3940 and miR-708, while their corresponding inhibitors eliminated it. CONCLUSION: T allele of rs59382073 in TBX2 3'UTR contributed to greater CHD risk in the Han Chinese population. G to T variation created binding sites for miR-3940 and miR-708 to inhibit gene expression.

Current practice and awareness of pediatric off-label drug use in Shanghai, China -a questionnaire-based study.

BACKGROUND: Off-label drug use is widespread in pediatric drug treatment, and the implementation of guidelines on this topic remains challenging. The objective of this study was to evaluate current practice and awareness of healthcare professionals towards pediatric off-label drug use, as well as the barriers to guideline implementation among pediatric healthcare professionals in Shanghai, China. METHODS: A validated questionnaire was issued to representatives of pediatricians, pharmacists, nurses and administrators from hospitals with pediatric qualification in Shanghai. RESULTS: A total of 679 completed questionnaires from 69 hospitals were included in the analysis. Nearly half (47.9%) of the pediatricians acknowledged that they had prescribed off-label drugs. Most (88.4%) of the pharmacists acknowledged that they had dispensed off-label medicines. The main reason for off-label prescribing was the lack of pediatric dosage information. The most common category of off-label prescribing in children was dosage. Nearly half (42.0%) of the participating hospitals had developed internal protocols for off-label drug use. However, approximately half of the respondents reported that they did not adhere to the guidance and that it had barriers to implementation. Most respondents (84.5%) declared that they were familiar with the term "off-label drug use". However, the awareness rate of the Chinese Expert Consensus of Pediatric Off-Label Drug Use was low (45.7%). More than half (55.4%) of the respondents declared that they did not adhere to the process proposed in the consensus and that barriers existed for its utilization. CONCLUSIONS: Pediatric off-label drug use is widespread in Shanghai, China, and barriers exist to the implementation of the guideline. A legally recognized national guideline with a broad scope of application for off-label drug use is urgently needed; at the same time, more education and training on off-label drug use should be provided to targeted healthcare professionals.

MIB1 mutations reduce Notch signaling activation and contribute to congenital heart disease.

Congenital heart disease (CHD) is one of the most common birth defects in humans, but its genetic etiology remains largely unknown despite decades of research. The Notch signaling pathway plays critical roles in embryonic cardiogenesis. Mind bomb 1 (Mib1) is a vital protein that activates the Notch signaling pathway through promoting ubiquitination, endocytosis and subsequent activation of Notch ligands. Previous studies show that Mib1 knockout in mice completely abolishes Notch signaling, leading to cardiac deformity. However, the function of MIB1 and its potential disease-causing mutations are poorly studied in human CHD. In this research, we identified four novel non-synonymous heterozygous rare mutations of MIB1 from 417 Han Chinese CHD patients. The following biochemical analyses revealed that mutations p.T312K fs*55 and p.W271G significantly deplete MIB1's function, resulting in a lower level of JAGGED1 (JAG1) ubiquitination and Notch signaling induction. Our results suggest that pathologic variants in MIB1 may contribute to CHD occurrence, shedding new light on the genetic mechanism of CHD in the context of the Notch signaling pathway.

[Research advances in the pathogenesis of familial Kawasaki disease].

Kawasaki disease has become the leading cause of acquired heart disease in children in North America and Japan. The incidence rate of Kawasaki disease varies significantly across regions and races. The first-degree relatives of patients with Kawasaki disease have a significantly higher risk of this disease than the general population. This article reviews the onset of familial Kawasaki disease and possible pathogenesis.

Prenatal diagnosis of congenital heart diseases by fetal echocardiography in second trimester: a Chinese multicenter study.

INTRODUCTION: The objective of our study was to evaluate the performance of detailed fetal echocardiography by skilled obstetric physician sonologists in the diagnosis of congenital heart disease (CHD) in a Chinese population. MATERIAL AND METHODS: This investigation included a multicenter prospective cohort of 10 259 pregnant women attending 10 regional tertiary hospitals in China. The inclusion criteria were singleton pregnancy and gestational age from 18 to ≤28 weeks. Women with multiple pregnancies were excluded. A detailed fetal echocardiography was performed by trained physicians with at least 3 years of experience. The primary outcome measures included sensitivity, specificity, and positive and negative likelihood ratios of detailed fetal echocardiography in prenatal detection of CHD. RESULTS: The sensitivity and specificity of fetal echocardiography in detecting any CHD were 33.9 and 99.8%, respectively, in the low-risk population, and 68.8 and 99.4%, respectively, in the high-risk population. For detecting major CHDs, fetal echocardiography had a high sensitivity and specificity, and satisfactory positive and negative likelihood ratios in both the low-risk population (88.2, 100%, 6947.7, and 0.118, respectively) and high-risk population (100, 99.9%, 833.3, and <0.0001, respectively). The sensitivity and likelihood ratios were substantially lower for detecting minor CHDs in both populations. CONCLUSIONS: Detailed fetal echocardiography performed by skilled physicians had high detection rate for major CHD in both low-risk and high-risk populations. However, its value for detecting minor CHD was limited. The incorporation of fetal echocardiography with multiple cardiac views into routine ultrasound screening may improve the detection rate of fetal major CHD and facilitate appropriate parental counseling.

[Generation of tnnt2a knock-out zebrafish via CRISPR/Cas9 and phenotypic analysis].

Cardiac troponin T (cTnT) serves as a structural protein of myocardial fiber, and participates in heart excitation-contraction coupling process. Here, we generated tnnt2a (cTnT-coding gene) deletion mutant zebrafish via CRISPR/Cas9 technique, and performed phenotypic analysis of the identified tnnt2a mutants. We observed that there was no significant difference between heterozygous mutant and wild type zebrafish, and the homozygous mutants displayed significant malformations in heart, including cardiac arrest, atrium and ventricle enlargement, pericardium effusion, and the individuals usually died before 7 day post fertilization (dpf). We further analyzed the expression alternations of heart sarcomere genes (tnnt2a, actc1a, tpm4a, myl7, vmhc) at transcriptional level in tnnt2a-/-(Δ2) zebrafish by performing real time RT-PCR, and found that the RNA expression level of tnnt2a in tnnt2a-/- zebrafish decreased constantly at each time point of developmental stages, and actc1a, tpm4a, myl7 and vmhc all showed higher expressions at early developmental stages and lower expressions at late developmental stages, in comparison with those of wild type zebrafish. Lastly, electron microscopy on cardiac tissues suggested that there were significant changes of the thick or thin filament structures in tnnt2a-/-(Δ2) zebrafish, which was further confirmed by F-actin and Tpm4 immunofluorescence staining. The tnnt2a-/- zebrafish generated by CRISPR/Cas9 bears the most common symptoms of patients with dilated cardiomyopathy, and therefore can be used as a tool to study TNNT2-deficiency related cardiomyopathy.

[Research advances in the mechanism of congenital heart disease induced by pregestational diabetes mellitus].

Congenital heart disease (CHD) is the most common birth defect at present and has a complex etiology which involves the combined effect of genetic and environmental factors. Pregestational diabetes mellitus is significantly associated with the development of CHD, but the detailed mechanism remains unknown. This article reviews the research advances in the molecular mechanism of CHD caused by pregestational diabetes mellitus.

Human embryonic cardiovascular function.

INTRODUCTION: This review presents an overview of descriptive knowledge on human embryonic cardiovascular physiology mostly based on noninvasive assessment by Doppler ultrasonography. Our objective was to identify and analyze published studies on embryonic cardiovascular function, and summarize available knowledge in this field. MATERIAL AND METHODS: Citations related to human embryonic cardiovascular function were searched in PubMed, EMBASE, CINAHL and Web of Science using keywords and MeSH terms without any time limitation. The search was restricted to English language articles. Abstracts were screened and full texts of relevant articles were obtained. All articles that reported on physiological aspects of human embryonic cardiovascular function were included. Studies reporting on cardiovascular function after 10 weeks of gestation were excluded. Data were synthesized and presented narratively. RESULTS: We identified 10 studies that had evaluated cardiovascular function and/or hemodynamics in human embryos at ≤10 weeks of gestation. All of these reported only certain aspects of embryonic cardiovascular function. Embryonic heart rate is associated significantly with gestational age and increases from 6 to 10 weeks of gestation. Cardiac inflow is monophasic during the embryonic period and atria appear to generate higher force during contraction compared with ventricles. Both ventricular inflow and outflow velocities increase with advancing gestation, whereas the Tei index decreases significantly. During the embryonic period, placental blood flow increases with gestation, but absent umbilical artery diastolic flow and umbilical venous pulsations are normal phenomena. CONCLUSION: There are important differences in normal cardiovascular function between the embryonic and fetal stages of human in utero development.

[Role of the canonical Wnt signaling pathway in heart valve development].

Formation of the heart valves is one of critical steps in vertebrate cardiac development. Valvular heart anomaly can induce severe cardiac impairment, which is one of most common symptoms for congenital heart defects (CHD). The canonical Wnt/ß-catenin signaling pathway, which is essential for numerous developmental processes, has also been suggested to be involved in the regulation of proliferation, differentiation, and migration of myocardium, endocardium and valve primordia at different stages. The canonical Wnt signaling also regulates the endocardial-mesenchymal transformation (EMT) process during the endocardial cushion formation. This paper reviews current knowledge about the canonical Wnt signaling pathway in heart valve development, including the functional diversities of Wnt activity in heart valve development at different stages and its interaction with other valve-relevant signaling pathways and the potential role of canonical Wnt activity in heart valve mesenchymal stem cells at the late developmental stage.

Relationship between isolated mild tricuspid valve regurgitation in second-trimester fetuses and postnatal congenital cardiac disorders.

OBJECTIVES: In most cases, the clinical importance of fetal isolated mild tricuspid valve regurgitation is not known. This study evaluated the relationship between fetal isolated mild tricuspid regurgitation in the general obstetric population and postnatal congenital cardiac disorders. METHODS: Detailed fetal echocardiography was done between 18 and 24 weeks' gestation to detect tricuspid regurgitation and to exclude complicated cardiac defects. Routine second-trimester targeted organ scans were also performed to exclude extracardiac defects. Follow-up was done until birth. After birth, the cardiac anatomy of the neonates was examined by echocardiography. The association between fetal isolated mild tricuspid regurgitation and postnatal congenital cardiac disorders was assessed by logistic regression analysis. RESULTS: No major cardiac disorders were found postnatally. Some minor disorders were found, including a patent foramen ovale, atrial septal defects, a patent ductus arteriosus, and small ventricular septal defects. Fetuses with isolated mild tricuspid regurgitation had a significantly higher likelihood of having ventricular septal defects (odds ratio, 5.80; P = .027) or a patent foramen ovale with atrial septal defects and a patent ductus arteriosus (odds ratio, 11.61; P = .007). There was no significant association between tricuspid regurgitation and an isolated patent foramen ovale or a patent foramen ovale with atrial septal defects in neonates. CONCLUSIONS: Fetuses with isolated mild tricuspid regurgitation in the second trimester did not have a higher incidence of major cardiac disorders after birth. The presence of isolated mild tricuspid regurgitation may be an indication of minor postnatal congenital cardiac disorders.

miR-10a and miR-10b target the 3'-untranslated region of TBX5 to repress its expression.

As a well-known transcription factor, TBX5 is involved in embryonic cardiac development. Although TBX5 functions in a dose-dependent manner, the posttranscriptional regulation of human TBX5 is poorly understood. Thus, this study aimed to identify microRNAs that modulate TBX5 expression. Luciferase assays were used to screen miRNAs predicted to modulate TBX5 expression. Using quantitative reverse transcriptase-polymerase chain reaction and Western blot analysis, the authors found that miR-10a and miR-10b significantly repressed TBX5 expression and decreased TBX5 protein levels by targeting the TBX5 3'-untranslated region. In addition, miR-10a and miR-10b expression levels were respectively 2.77 and 3.51 times higher in the heart tissues of congenital heart disease patients than in healthy control subjects, suggesting that they are potential diagnostic biomarkers. In conclusion, the study results indicate that miR-10a and miR-10b inhibit TBX5 expression at the level of translation. Higher levels of miR-10a and miR-10b expression are associated with a higher risk of congenital heart defects.